KMBC 9 News recently followed a group of school staffers as they underwent the emotional training.

Officials with the Liberty School District said they had already planned to hold the training days before the shootings in Newtown, Conn. They said after it happened, it made them realize how important the training is for their staff.

"A child in America hasn't died in a school fire in 50 years because we decided as a culture that was unacceptable, so we put systems in place," said Todd Burke of Strategos International. "Now we're dealing with a different type of threat."

Burke's company teaches intruder response courses and has expanded its services to include school crisis casualty care.

He said before Sandy Hook, he fielded two or three phone calls per day. Now, he said the company is getting two or three dozen phone calls every day and about 100 emails.

"I'm sad for the reason we're busy," he said.

His courses help teach school staff members what to do when gunfire stops.

He said medical first responders are often trained to wait until the crisis scene is safe and secure before coming in to help victims, giving people inside precious little time to help save a life.

"It's very hard. I can picture kids I would need to take care of, and I can imagine what I would need to do to take care of those kids in those scenarios in the buildings and where I would go. It's very scary," said Shoal Creek Elementary nurse Kristin Redmond.

Attendees learn everything from how to control bleeding from a gunshot wound to how to move someone out of harm's way fast.

"I hope I never have to use this, but if I do, this could save a life (because) I was here today," said Warren Hills Elementary School music teacher Laurie Walker.